---2003 Disco II---
I have a combination of codes pulling with the 'check engine soon" light on:
P1415 -P1412 [normally combined = SAI solenoid but other issues arise I notice not a clear answer for solution]

P0171 -too lean[combined w/ P1171 Bank 1 LH Bank front sensor open circuit]
P1171 -[some same PCV hoses need replaced or cleaned]
P0134 -no activity on O2sensor1

---SYMPTOMS---
-Runs rougher than normal at idle
-Runs rougher than normal at slow speeds
-MPG is slightly lower and more noticeably lower under half a tank

A. Please advise if the combination of codes = a specific problem or seen combo of them similarly?

B. Anything specific that I can refer back to Workshop Manual to fix for any combination of the codes?

--HISTORY--
1. Changed plugs
2. Changed wires 8mm
3. Cleaned Valve Covers + new gaskets an seal
4. Clean Upper Manifold + new gasket
5. Check for air/vacuum leaks in around manifold an non seen
6. Checked hoses for cracks an leaks - non visible

 

I have both the P1412 and P1415 codes myself so I will be interested in responses you get around those. Can you elaborate on what the SAI solenoid is and where it's located. A solenoid should be testable with a meter.

 

P1415 - SAI runs when the vechical is cold. The SAI Pump runs, blows fresh air into the rail. Power is applied to the vacuum switching valve, which applies vaccum to the gulp valves so they open. You either have no fresh air or no vacuum to open the valves. The nipple at the reservoir behind the right wheelhouse gets oil-soaked and falls off. The vacuum valves fail as well.

P1171 can mean a vaccum leak among other things, Based on this logic, I would guess that the vaccum line to one of the switching valves is loose, broken or off, or the switching valve is bad. But I'm not that smart so I could be wrong.

 

Hello doyle,

Questions:

1-SAI- you are speaking about the Vacuum solenoid valve correct?
-Yes, my concern is that the solenoid is simply not functional properly an needs replaced. [Page 17-2-29 in workshop manual]
--The nipple at the reservoir behind the right wheelhouse--? what is this exactly?

2-Which vacuum line to switching valves you referring too?
--My concern here is that the IACV itself is not functional since it controls idle and has the hoses coming in and through the the upper manifold and NO hoses have any apparent issues or leaks.

 

Ok, thank you for the response. I checked that pump (SAI) the hose off the bottom is intact as it the stainless tubing along the firewall that routes to the two cans over either exhaust manifold. I have had the codes for a few weeks now and had been hearing the pump upon first starting the truck. Today no screaming pump no noise at all. Is it safe to say that the pump should be getting power on every cold start? If so I can check for voltage at that time and go from there. I assume its not the motor that burns out but rather the impeller falling apart and jamming hence the loud noisy pump.